Rachel Castillo was reported missing on November 10.
CNN  — 

Human remains found in a remote California location are those of a mother reported missing Thursday after a “significant amount of blood” was seen in her home, authorities say.

In a news release, the Simi Valley Police Department said the remains of Rachel Castillo, 25, were discovered in Los Angeles County’s Antelope Valley, and her ex-husband has since been taken into custody.

Castillo was reported missing on November 10 by her sister, who had arrived home at the residence they shared and “found evidence that a struggle occurred inside,” according to Simi Valley police. Castillo was missing but her personal belongings – including her cell phone and car keys – were still at the apartment, police said.

“Based on evidence at the scene, officers suspected that a crime involving serious injury occurred,” the release said. “Detectives have been working continuously since that time to locate Rachel and develop leads in the case.”

Castillo’s ex-husband, Zarbab Ali of Hawthorne, California, is the primary suspect in the case, police said. After the Antelope Valley remains were identified as Castillo, Ali was arrested Sunday afternoon at his parent’s home in Victorville in connection with her homicide, they said.

It is unclear if Ali has an attorney of record at this time.

Rachel’s mother, Robyn Castillo, spoke with CNN Saturday before Rachel’s body was discovered. Robyn described her daughter – who had sons aged 5 and 2 – as a “really great mom to her sons, a good daughter, a good sister, and a good friend.”

Rachel had been studying to become a marriage and family therapist, her mother said. She added that Rachel loves to help people and get them the resources they need.

“It’s been very difficult, we’re just taking it day by day and moment by moment and helping police as much as we can,” Robyn said.

CNN’s Sharif Paget, Melissa Alonso and Rebekah Riess contributed to this report.